What Is CAR-T Cell Therapy? Can It Really Treat Cancer, Who Is It Suitable For, and What Should You Know Before Treatment?

Normally, T cells are a type of white blood cell that play an important role in the body’s immune system. Their function is to detect and eliminate abnormal cells, such as cells infected by viruses or other pathogens, cells that have undergone abnormal changes, as well as cancer cells. This process relies on recognizing antigens (Antigens) present on the surface of cells.

However, some cancer cells can evade immune detection, making it difficult for T cells to recognize them and preventing an effective immune response against the cancer. CAR-T Cell Therapy, or Chimeric Antigen Receptor T-cell Therapy, was therefore developed to help overcome this limitation.

The treatment involves collecting T cells from the patient or, in selected cases, from a suitable donor and genetically modifying them in a laboratory so that they express a special receptor called a CAR (Chimeric Antigen Receptor). This receptor allows T cells to recognize and bind more precisely to specific target antigens on the surface of cancer cells. The modified CAR-T cells are then expanded in the laboratory until a sufficient number is obtained for treatment before being infused back into the patient through a vein.

Once CAR-T cells enter the body, these modified cells use their specialized receptors to identify and bind to specific antigens on cancer cells, such as CD19, which is found on certain B-cell malignancies, or BCMA, which is commonly targeted in multiple myeloma. The CAR-T cells then release substances such as perforin and granzyme to destroy the cancer cells.

At the same time, CAR-T cells release cytokines (Cytokines) that help activate the immune response and may continue to proliferate and persist in the body for a period of time. This can contribute to disease control and, in some patients, may help produce a more durable treatment response.

CAR-T Cell Therapy can be an effective treatment option for certain types of cancer, particularly some blood cancers and lymphomas that have not responded to standard treatments or have relapsed. Although this therapy does not result in a cure in every case, clinical evidence has shown that some patients can achieve a strong response, enter remission, and maintain a treatment response for several years.

According to long-term follow-up data from the ZUMA-1 study in patients with refractory Large B-cell Lymphoma, Axicabtagene Ciloleucel, or Axi-cel, achieved an overall response rate of 83% and a complete response rate of 58%. Some patients continued to maintain their response over the long term (Neelapu et al., 2023). These findings suggest that CAR-T Cell Therapy may have the potential to provide durable disease control in certain patients.

Long-term follow-up of approximately three years from the ELIANA study in children and young adults with relapsed or refractory B-cell Acute Lymphoblastic Leukemia (B-ALL) found that Tisagenlecleucel enabled many patients to achieve remission, with some maintaining their treatment response for several years (Laetsch et al., 2023).

Meanwhile, a long-term review of CAR-T Cell Therapy reported that CD19-targeted CAR-T cells may help some patients with B-cell malignancies achieve long-lasting remission and may have curative potential in selected patient groups. However, treatment outcomes can vary depending on multiple factors. For BCMA-targeted CAR-T cells in patients with Multiple Myeloma, although response rates can be favorable, the duration of remission is generally shorter compared with CD19 CAR-T therapy in B-cell malignancies (Cappell & Kochenderfer, 2023).

Therefore, CAR-T Cell Therapy can be considered another treatment option for certain cancers, with the potential to help control disease and allow some patients to experience longer periods of remission. However, outcomes vary depending on several factors, including the type of cancer, stage of disease, tumor burden, the patient’s overall health, immune system response, and complications that may occur following treatment.

The differences between CAR-T Cell Therapy and conventional cancer treatments can be summarized as follows:

• Treatment approach CAR-T Cell Therapy is a form of immunotherapy that involves modifying a patient’s T cells to express a special receptor capable of recognizing and targeting specific cancer cells. In contrast, standard cancer treatments use different approaches depending on the disease, such as surgery to remove tumors, radiation therapy to destroy or inhibit the growth of cancer cells, chemotherapy to target rapidly dividing cells, and targeted therapy for patients whose cancer has specific molecular targets that match the treatment.
• Suitable patient groups CAR-T Cell Therapy is generally considered for patients with certain blood cancers and lymphomas that have not responded to standard treatments or have relapsed. In comparison, conventional treatments can be used for a much broader range of cancers, depending on the individual patient and characteristics of the disease.
• Specificity toward cancer cells CAR-T Cell Therapy is designed to recognize specific target antigens on the surface of cancer cells, allowing it to act more selectively against targeted cells and potentially reduce effects on unrelated normal cells. Chemotherapy, on the other hand, targets rapidly dividing cells and may therefore also affect normal rapidly dividing cells, such as blood cells, hair follicle cells, and cells lining the gastrointestinal tract. Radiation therapy may affect normal cells located near the treatment area. Targeted therapy can offer greater specificity, but it is only suitable for patients whose cancer has the specific molecular target that the medication is designed to act against.

• Patients with certain blood cancers or lymphomas that have not responded to standard treatments or have relapsed.
• Patients whose overall health and major organ functions, including the heart, lungs, liver, and kidneys, are considered suitable for treatment.
• Patients who are able to undergo close medical monitoring and follow-up after treatment.

Whether a patient is suitable for CAR-T Cell Therapy must be assessed individually by a specialist physician.

【English】

CAR-T Cell Therapy is a personalized cancer treatment process consisting of several key steps:

• Pre-treatment health assessment The doctor evaluates the type of cancer, stage of the disease, previous treatment history, and the patient’s overall health to determine an appropriate treatment plan.
• Collection of T cells from the patient’s blood Blood is collected through a vein and processed using leukapheresis to separate T cells from the other blood components. The remaining blood components are then returned to the patient’s body.
• Modification of T cells in the laboratory The collected T cells are genetically modified to express CAR receptors, enabling them to recognize and bind more specifically to target cancer cells.
• Expansion of CAR-T cells Once the cells have been successfully modified, the CAR-T cells are cultured and expanded until a sufficient number is available for treatment. This process may take several weeks. During this waiting period, the doctor may provide additional treatment to help control the disease.
• Preparing the body before CAR-T cell infusion Patients usually receive low-dose chemotherapy before the CAR-T cell infusion to reduce certain immune cells and prepare the body for the newly infused cells.
• CAR-T cell infusion The CAR-T cells are infused back into the patient through a vein. The infusion generally takes approximately 30–45 minutes, although it may take longer in some cases.
• Monitoring after treatment After receiving CAR-T cells, patients may need to remain in a hospital or treatment center for approximately 1–2 weeks so that their response to treatment and any potential side effects can be closely monitored. Once the patient’s condition is stable, the doctor may allow them to return home. However, some patients may need to remain close to the hospital or treatment center for an additional period, depending on the doctor’s assessment.

• CAR-T Cell Therapy can only be used for certain types of cancer, particularly some blood cancers and lymphomas that have clearly identifiable target antigens on the surface of cancer cells.
• It is not a first-line treatment for most patients. Doctors generally consider CAR-T Cell Therapy for patients whose cancer has not responded to standard treatments or has relapsed.
• The cost is relatively high because the treatment requires advanced technology and individualized cell preparation.
• The treatment process takes time. It may take approximately 2–4 months, or longer in some cases. Therefore, patients generally need to be in an appropriate overall health condition and have sufficient time available for the treatment process.
• Close monitoring is required after treatment. Patients may need to stay in the hospital for approximately 1–2 weeks. After discharge, they may be advised to remain close to the treatment center until about 4 weeks after CAR-T Cell Therapy so that medical care can be accessed promptly if any abnormal symptoms occur. Regular follow-up appointments are also required.

English

CAR-T Cell Therapy can be an effective cancer treatment when performed under the supervision of an experienced medical team in an appropriately equipped healthcare facility. However, the treatment may cause side effects that require close monitoring, particularly during the early period after treatment, including:

• Cytokine Release Syndrome (CRS) CRS occurs when the immune system becomes excessively activated after CAR-T cells are infused into the body. Symptoms may include fever, chills, low blood pressure, difficulty breathing, and fatigue. In severe cases, CRS may lead to dysfunction or failure of major organs.
• Neurological side effects (ICANS) Some patients may develop Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS), which may cause confusion, dizziness, difficulty speaking or communicating, drowsiness, hand tremors, muscle twitching, balance problems, or seizures in some cases.
• Low blood cell and platelet counts Reduced blood cell and platelet levels may cause fatigue, anemia, an increased tendency to bleed, and easier bruising than usual.
• Risk of infection The immune system may be weakened during the early period after treatment, increasing susceptibility to infections. Patients should therefore maintain strict hygiene practices, closely monitor their condition, and seek medical attention immediately if any unusual symptoms occur.

日本語

CAR-T細胞療法（CAR-T Cell Therapy）は、経験豊富な医療チームの管理のもと、適切な設備を備えた医療機関で行われることで、特定のがんに対して有効性が期待できる治療法です。ただし、特に治療初期には、注意深い経過観察が必要となる副作用が生じる可能性があります。

• サイトカイン放出症候群（Cytokine Release Syndrome: CRS） CAR-T細胞の投与後に免疫システムが過剰に反応することで起こる状態です。発熱、悪寒、血圧低下、呼吸困難、倦怠感などがみられることがあります。重症の場合には、重要な臓器の機能障害や臓器不全につながる可能性があります。
• 神経系の副作用（ICANS） Immune Effector Cell-Associated Neurotoxicity Syndrome（ICANS）と呼ばれる神経系の副作用が生じる場合があります。症状としては、混乱、めまい、会話やコミュニケーションの困難、強い眠気、手の震え、筋肉のけいれん、バランス障害、場合によってはけいれん発作などがみられることがあります。
• 血球減少・血小板減少 血球や血小板が減少することで、倦怠感、貧血、出血しやすくなる、あざができやすくなるなどの症状が現れることがあります。
• 感染症のリスク 治療後の初期には免疫機能が低下する場合があり、感染症にかかりやすくなる可能性があります。そのため、衛生管理を徹底し、体調を注意深く観察することが重要です。異常な症状がみられた場合は、速やかに医療機関を受診してください。

中文

CAR-T细胞疗法（CAR-T Cell Therapy）在专业医疗团队的监督下，并于具备相应医疗条件的机构中进行时，可作为某些癌症的有效治疗方式。然而，该治疗可能引起一些需要密切监测的副作用，尤其是在治疗初期，包括：

• 细胞因子释放综合征（Cytokine Release Syndrome: CRS） CRS是CAR-T细胞进入人体后，免疫系统出现过度激活所引起的一种反应。患者可能出现发热、寒战、血压下降、呼吸困难及疲倦等症状。严重情况下，可能导致重要器官功能障碍甚至器官衰竭。
• 神经系统异常（ICANS） 部分患者可能出现免疫效应细胞相关神经毒性综合征（Immune Effector Cell-Associated Neurotoxicity Syndrome: ICANS），表现为意识混乱、头晕、言语或沟通困难、嗜睡、手部震颤、肌肉抽动、平衡障碍，部分患者还可能出现癫痫发作。
• 血细胞减少及血小板减少 血细胞及血小板数量下降可能导致疲劳、贫血、容易出血以及较平时更容易出现瘀青等情况。
• 感染风险增加 治疗后的早期阶段，免疫系统功能可能暂时下降，从而增加感染风险。因此，患者应严格保持个人卫生，并持续观察自身状况。如出现任何异常症状，应立即就医。

العربية

يمكن أن يكون العلاج بخلايا CAR-T (CAR-T Cell Therapy) علاجًا فعالًا لبعض أنواع السرطان عندما يتم تحت إشراف فريق طبي متخصص وفي منشأة صحية مجهزة وفق المعايير المناسبة. ومع ذلك، قد يسبب هذا العلاج بعض الآثار الجانبية التي تتطلب مراقبة دقيقة، خاصة خلال الفترة الأولى بعد العلاج، ومنها:

• متلازمة إطلاق السيتوكينات (Cytokine Release Syndrome: CRS) تحدث هذه الحالة نتيجة الاستجابة المفرطة للجهاز المناعي بعد إعطاء خلايا CAR-T. وقد تشمل الأعراض ارتفاع درجة الحرارة، والقشعريرة، وانخفاض ضغط الدم، وصعوبة التنفس، والإرهاق. وفي الحالات الشديدة، قد تؤدي إلى اضطراب وظائف الأعضاء الحيوية أو فشلها.
• اضطرابات عصبية (ICANS) قد يصاب بعض المرضى بمتلازمة السمية العصبية المرتبطة بالخلايا المناعية الفعالة (Immune Effector Cell-Associated Neurotoxicity Syndrome: ICANS)، والتي قد تسبب الارتباك، والدوخة، وصعوبة الكلام أو التواصل، والنعاس، وارتجاف اليدين، والتشنجات العضلية، واضطرابات التوازن، وقد تحدث نوبات تشنج لدى بعض المرضى.
• انخفاض خلايا الدم والصفائح الدموية قد يؤدي انخفاض عدد خلايا الدم والصفائح الدموية إلى الشعور بالإرهاق، وفقر الدم، وزيادة قابلية النزيف، وسهولة ظهور الكدمات مقارنة بالمعتاد.
• زيادة خطر الإصابة بالعدوى قد تنخفض كفاءة الجهاز المناعي خلال الفترة الأولى بعد العلاج، مما يزيد من احتمالية الإصابة بالعدوى. لذلك، ينبغي على المريض الالتزام بالنظافة الشخصية بدقة ومراقبة حالته الصحية باستمرار. وفي حال ظهور أي أعراض غير طبيعية، يجب مراجعة الطبيب فورًا.

Before Undergoing CAR-T Cell Therapy

Patients should strictly follow their doctor’s instructions when preparing for CAR-T Cell Therapy. Recommendations include:

• Provide the doctor with a complete medical history, including underlying conditions, current medications and supplements, any history of drug or substance allergies, previous surgeries, and prior cancer treatments.
• Undergo all health assessments requested by the doctor. These may include blood tests, evaluation of major organ function such as the heart, lungs, kidneys, and liver, and screening for infections. In some cases, bone marrow examination, CT scan, or MRI may also be considered.
• Get adequate rest and eat nutritious food to help prepare the body before cell collection.
• Maintain good overall health, avoid crowded places, and avoid close contact with people who are ill.
• Arrange for a caregiver in advance. After receiving CAR-T cells, patients may develop side effects that require close monitoring, particularly during the first 4 weeks after treatment.

After CAR-T Cell Therapy, the following self-care recommendations should be followed:

• Patients should avoid driving, operating machinery, or using tools that may pose a risk of injury for at least 8 weeks.
• Avoid crowded places during periods of reduced immunity. Wash your hands frequently and maintain good hygiene to reduce the risk of infection.
• Check your temperature 1–2 times per day and keep a record to monitor any changes or trends in body temperature.
• Eat nutritious, freshly prepared food. Avoid leftover food and raw or undercooked foods.
• Drink clean water in the amount recommended by your doctor. Avoid alcoholic beverages and caffeine.
• Get adequate sleep and rest. Avoid strenuous activities and intense exercise. During recovery, light activities such as walking or gentle yoga may be appropriate, according to your doctor’s advice.
• Attend all scheduled follow-up appointments and take medications exactly as prescribed. Do not stop or adjust medications, or take additional supplements or herbal products, without consulting your doctor.
• If any unusual symptoms occur, such as chills, a fever above 38°C, difficulty breathing, nausea, vomiting, or new neurological symptoms, seek medical attention immediately.